Modern optical systems should meet ever more stringent requirements in respect of image quality. To this end, use may be made of highly precise and high-quality optical units. Alternatively, use may be made of more cost-effective optical units in combination with subsequent postprocessing.
Higher-quality optical units may be used to generate high-quality images. However, in addition to disadvantages in terms of costs, this may also lead to a large installation space and a high weight. Moreover, a large number of lenses may increase the reflection susceptibility of the system and/or reduce the transmission. This may be disadvantageous for many applications, for example in the field of expensive specialist appliances.
Apparatuses and methods which combine cheaper optical units with subsequent postprocessing may contain deconvolution techniques in the digital further processing. Such techniques are often connected with high computational outlay. This may be found to be disadvantageous, in particular, if a fast calculation of an image is desired, for example for the real-time display of recorded specimen regions in a microscope system. A low contrast of the modulation transfer function (MTF) and/or a poor signal-to-noise ratio (SNR) of the image may lead to certain spatial frequencies determined using deconvolution techniques not being reconstructable or only being reconstructable under certain additional assumptions. By way of example, this may be the case for spatial frequency regions in which, on account of aberrations, the MTF has zeros. By way of example, such zeros in the MTF may occur in the case of astigmatism or defocus. Longitudinal chromatic aberrations may not be easily compensable by means of deconvolution techniques.